Discovery of Five Previously Misidentified BY Draconis Stars in ASAS Data (Poster abstract)

Volume 43 number 1 (2015)

Jessica Johnson

Department of Physics and Earth Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06050; johnsonj@my.ccsu.edu

Kristine Larsen

Department of Physics and Earth Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053; Larsen@ccsu.edu

Abstract

(Abstract only) This work is a continuation of an ongoing project first presented at the 2013 Annual Meeting of the AAVSO. The original poster introduced a spreadsheet of 3,548 computer-classified candidate Cepheid variable stars in the ASAS (All Sky Automated Survey) photometry data, a data set that was known to contain many false positive identifications. Previous work by Patrick Wils suggested that BY Draconis stars (spotted K and M dwarfs) were an important source of misidentifications in this sample. The authors have undertaken a project to systematically identify previously unknown BY Draconis stars in this data set. This is initially done through the investigation of the stars’ known physical properties (for example, from infrared photometry [2MASS] and proper motion [PPMXL] data). An analysis of light curves and phase plots is the final step in identifying BY Draconis stars, for example searching for characteristic changes in mean magnitude and amplitude. Thus far five previously unknown BY Draconis stars have been identified through this process.